Change in Allowance for Doubtful Accounts (Detail) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jul. 31, 2012
Allowance for Doubtful Accounts Receivable [Roll Forward]
Beginning Balance	$ 4,432
Charged to expense	32
Deductions	(145)	[1]
Ending Balance	$ 4,319

[1] Specific account write-offs and foreign exchange.